This application claims the benefit of foreign priority from International Application No. PCT/DE99/01251, which was published as International Publication No. WO 00/30231 in the German language on May 25, 2000, and which claims the benefit of foreign priority from German Patent Application Serial No. 198 53 203.2 filed Nov. 18, 1998.
1. Field of the Invention
The present invention relates to a cable sleeve comprising a covering body and at least one front-face sealing body with a circumferential, U-shaped sealing groove and a ring seal. The covering body comprises at its front-face end a circumferential, conically tapered flange which, together with the ring seal inserted into the sealing groove, is engaged by a straining ring.
2. Description of the Related Art
EP 0 877 716-A2 discloses a cable sleeve which comprises a covering body comprising an added flange, to which a sealing system comprising an annular seal is pressed with the help of a straining ring.
EP 0 844 717-A2 discloses a straining ring for flanged joints in cable sets or tubes. The straining ring comprises several partial ring segments that are engaged by a straining band. During straining of the straining band, the partial ring segments are radially inwardly pressed onto a sealing system.
WO 96/32660 discloses a hood sleeve formed of a sealing body and a hood body. A sealing ring is housed in a sealing groove comprising a variable volume. As a result of deformation that occurs during closing, the sealing ring is pressed to the inner wall of the hood body by narrowing the sealing groove, for example with the help of an eccentric.
The problem underlying the present invention is to create a cable sleeve, in which the sealing ratios between the sealing body and the covering body are improved with the help of a suitable ring seal and a straining ring being adapted thereto. According to the present invention, the problem is solved with a cable sleeve of the above-mentioned type wherein the ring seal comprises as its basic cross-section an L-shape. The cross-section of the first leg of the L-shape is adapted to that of the sealing groove of the sealing body and the second leg of the L-shape has at both of its sides a tapered cross-section broadening towards the first leg. The tapered course of the second leg corresponds at the one side of the course of the tapered flange and at the other side to the course of the conical groove wall of the ring groove inside the straining ring. The straining ring comprises a circumferential projection acting on the first leg of the ring seal positioned in the sealing groove of the sealing body.
As compared to the known prior art, it is a decisive advantage in the sealing system according to the present invention that the straining ring exerting the sealing pressure not only effects an all-over deformation of the ring seal, but that, during the closing operation, the sealing towards the covering body is done via the groove wall of the ring groove of the straining ring and the sealing towards the sealing body is done via the action of a circumferential projection on the ring seal. For this reason the ring seal is formed to have an L-shaped basic form, wherein the first leg, which is in general the shorter one, is adapted to the shape of the groove of the sealing body. The second leg of the L-shaped ring seal is formed to have a conical shape and serves for sealing against a circumferential flange of the covering body. The circumferential ring groove in the straining ring is formed to have a corresponding conical shape, so that, when the straining ring is closed and its diameter is reduced, the straining ring slides along on the conical counter-surfaces. As a result, an increasing pressure is exerted on the ring seal, wherein the circumferential projection at the straining ring exerts pressure on the first leg of the ring seal. Further, guiding elements having the shape of a fixing groove and that of a fixing projection are provided in the straining ring and in the sealing body, respectively, for mutual positioning. The straining ring according to the present invention comprises several straining ring parts, and preferably two identical straining ring parts, which are fastened on the sealing region by means of closing elements. The closing elements are preferably threaded bolts or screws arranged in pivot bearings so as to be non-removable and can, after positioning of the straining ring parts, be threaded into counter-bearings of the corresponding straining ring part. The straining ring parts are pulled against each other by threading the screws of the straining ring and thereby pressing the sealing system together in the above-described manner.